- relaxed to accommodate overlay linking timeouts
[oweals/gnunet.git] / src / testbed / testbed_api.c
index 5070d4f29c19b1667e129c91da56ccc6add9b434..ebb9496f2805a4d840f7d622e2f8f8b9ae063369 100644 (file)
@@ -40,6 +40,7 @@
 #include "testbed_api.h"
 #include "testbed_api_hosts.h"
 #include "testbed_api_peers.h"
+#include "testbed_api_operations.h"
 
 /**
  * Generic logging shorthand
 #define TIMEOUT_REL TIME_REL_SECS(1)
 
 
+/**
+ * Testbed Helper binary name
+ */
+#define HELPER_TESTBED_BINARY "gnunet-helper-testbed"
+#define HELPER_TESTBED_BINARY_SSH ". ~/.bashrc; gnunet-helper-testbed"
+
+
+/**
+ * Handle for controller process
+ */
+struct GNUNET_TESTBED_ControllerProc
+{
+  /**
+   * The process handle
+   */
+  struct GNUNET_HELPER_Handle *helper;
+
+  /**
+   * The host where the helper is run
+   */
+  struct GNUNET_TESTBED_Host *host;
+
+  /**
+   * The controller error callback
+   */
+  GNUNET_TESTBED_ControllerStatusCallback cb;
+
+  /**
+   * The closure for the above callback
+   */
+  void *cls;
+
+  /**
+   * The send handle for the helper
+   */
+  struct GNUNET_HELPER_SendHandle *shandle;
+
+  /**
+   * The message corresponding to send handle
+   */
+  struct GNUNET_MessageHeader *msg;
+
+  /**
+   * The port number for ssh; used for helpers starting ssh
+   */
+  char *port;
+
+  /**
+   * The ssh destination string; used for helpers starting ssh
+   */
+  char *dst;
+
+  /**
+   * The configuration of the running testbed service
+   */
+  struct GNUNET_CONFIGURATION_Handle *cfg;
+
+};
+
+
 /**
  * The message queue for sending messages to the controller service
  */
@@ -80,7 +141,7 @@ struct MessageQueue
    * next pointer for DLL
    */
   struct MessageQueue *next;
-  
+
   /**
    * prev pointer for DLL
    */
@@ -154,6 +215,73 @@ struct GNUNET_TESTBED_HostRegistrationHandle
 };
 
 
+/**
+ * Context data for forwarded Operation
+ */
+struct ForwardedOperationData
+{
+
+  /**
+   * The callback to call when reply is available
+   */
+  GNUNET_CLIENT_MessageHandler cc;
+
+  /**
+   * The closure for the above callback
+   */
+  void *cc_cls;
+
+};
+
+
+/**
+ * Context data for get slave config operations
+ */
+struct GetSlaveConfigData
+{
+  /**
+   * The id of the slave controller
+   */
+  uint32_t slave_id;
+
+};
+
+
+/**
+ * Context data for controller link operations
+ */
+struct ControllerLinkData
+{
+  /**
+   * The controller link message
+   */
+  struct GNUNET_TESTBED_ControllerLinkMessage *msg;
+
+};
+
+
+/**
+ * Returns the operation context with the given id if found in the Operation
+ * context queues of the controller
+ *
+ * @param c the controller whose queues are searched
+ * @param id the id which has to be checked
+ * @return the matching operation context; NULL if no match found
+ */
+static struct OperationContext *
+find_opc (const struct GNUNET_TESTBED_Controller *c, const uint64_t id)
+{
+  struct OperationContext *opc;
+
+  for (opc = c->ocq_head; NULL != opc; opc = opc->next)
+  {
+    if (id == opc->id)
+      return opc;
+  }
+  return NULL;
+}
+
+
 /**
  * Handler for GNUNET_MESSAGE_TYPE_TESTBED_ADDHOSTCONFIRM message from
  * controller (testbed service)
@@ -173,8 +301,8 @@ handle_addhostconfirm (struct GNUNET_TESTBED_Controller *c,
 
   rh = c->rh;
   if (NULL == rh)
-  {  
-    return GNUNET_OK;    
+  {
+    return GNUNET_OK;
   }
   if (GNUNET_TESTBED_host_get_id_ (rh->host) != ntohl (msg->host_id))
   {
@@ -187,20 +315,20 @@ handle_addhostconfirm (struct GNUNET_TESTBED_Controller *c,
   if (sizeof (struct GNUNET_TESTBED_HostConfirmedMessage) == msg_size)
   {
     LOG_DEBUG ("Host %u successfully registered\n", ntohl (msg->host_id));
-    GNUNET_TESTBED_mark_host_registered_at_  (rh->host, c);
+    GNUNET_TESTBED_mark_host_registered_at_ (rh->host, c);
     rh->cc (rh->cc_cls, NULL);
     GNUNET_free (rh);
     return GNUNET_OK;
-  } 
+  }
   /* We have an error message */
   emsg = (char *) &msg[1];
-  if ('\0' != emsg[msg_size - 
-                   sizeof (struct GNUNET_TESTBED_HostConfirmedMessage)])
+  if ('\0' !=
+      emsg[msg_size - sizeof (struct GNUNET_TESTBED_HostConfirmedMessage)])
   {
     GNUNET_break (0);
     GNUNET_free (rh);
     return GNUNET_NO;
-  }  
+  }
   LOG (GNUNET_ERROR_TYPE_ERROR, _("Adding host %u failed with error: %s\n"),
        ntohl (msg->host_id), emsg);
   rh->cc (rh->cc_cls, emsg);
@@ -209,6 +337,29 @@ handle_addhostconfirm (struct GNUNET_TESTBED_Controller *c,
 }
 
 
+/**
+ * Handler for forwarded operations
+ *
+ * @param c the controller handle
+ * @param opc the opearation context
+ * @param msg the message
+ */
+static void
+handle_forwarded_operation_msg (struct GNUNET_TESTBED_Controller *c,
+                               struct OperationContext *opc,
+                               const struct GNUNET_MessageHeader *msg)
+{
+  struct ForwardedOperationData *fo_data;
+
+  fo_data = opc->data;
+  if (NULL != fo_data->cc)
+    fo_data->cc (fo_data->cc_cls, msg);
+  GNUNET_CONTAINER_DLL_remove (c->ocq_head, c->ocq_tail, opc);
+  GNUNET_free (fo_data);
+  GNUNET_free (opc);
+}
+
+
 /**
  * Handler for GNUNET_MESSAGE_TYPE_TESTBED_ADDHOSTCONFIRM message from
  * controller (testbed service)
@@ -223,65 +374,596 @@ handle_opsuccess (struct GNUNET_TESTBED_Controller *c,
                   const struct
                   GNUNET_TESTBED_GenericOperationSuccessEventMessage *msg)
 {
-  struct GNUNET_TESTBED_Operation *op;
-  struct GNUNET_TESTBED_EventInformation *event;
+  struct OperationContext *opc;
+  struct GNUNET_TESTBED_EventInformation event;
   uint64_t op_id;
-  
+
   op_id = GNUNET_ntohll (msg->operation_id);
-  LOG_DEBUG ("Operation %ul successful\n", op_id);
-  for (op = c->op_head; NULL != op; op = op->next)
+  LOG_DEBUG ("Operation %lu successful\n", op_id);
+  if (NULL == (opc = find_opc (c, op_id)))
   {
-    if (op->operation_id == op_id)
-      break;
+    LOG_DEBUG ("Operation not found\n");
+    return GNUNET_YES;
   }
-  if (NULL == op)
+  event.type = GNUNET_TESTBED_ET_OPERATION_FINISHED;
+  event.details.operation_finished.operation = opc->op;
+  event.details.operation_finished.op_cls = opc->op_cls;
+  event.details.operation_finished.emsg = NULL;
+  event.details.operation_finished.generic = NULL;
+  switch (opc->type)
+  {
+  case OP_FORWARDED:
+    {
+      handle_forwarded_operation_msg
+         (c, opc, (const struct GNUNET_MessageHeader *) msg);
+      return GNUNET_YES;
+    }
+    break;
+  case OP_PEER_DESTROY:
+    {
+      struct GNUNET_TESTBED_Peer *peer;
+      
+      peer = opc->data;
+      GNUNET_free (peer);
+      opc->data = NULL;
+      //PEERDESTROYDATA
+    }
+    break;
+  case OP_LINK_CONTROLLERS:
+    {
+      struct ControllerLinkData *data;
+      
+      data = opc->data;
+      GNUNET_assert (NULL != data);      
+      GNUNET_free (data);
+      opc->data = NULL;
+    }
+    break;
+  default:
+    GNUNET_assert (0);
+  }  
+  GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  opc->state = OPC_STATE_FINISHED;
+  if (0 != (c->event_mask & (1L << GNUNET_TESTBED_ET_OPERATION_FINISHED)))
+  {
+    if (NULL != c->cc)
+      c->cc (c->cc_cls, &event);
+  }
+  else
+    LOG_DEBUG ("Not calling callback\n");
+  return GNUNET_YES;
+}
+
+
+/**
+ * Handler for GNUNET_MESSAGE_TYPE_TESTBED_PEERCREATESUCCESS message from
+ * controller (testbed service)
+ *
+ * @param c the controller handle
+ * @param msg message received
+ * @return GNUNET_YES if we can continue receiving from service; GNUNET_NO if
+ *           not
+ */
+static int
+handle_peer_create_success (struct GNUNET_TESTBED_Controller *c,
+                            const struct
+                            GNUNET_TESTBED_PeerCreateSuccessEventMessage *msg)
+{
+  struct OperationContext *opc;
+  struct PeerCreateData *data;
+  struct GNUNET_TESTBED_Peer *peer;
+  GNUNET_TESTBED_PeerCreateCallback cb;
+  void *cls;
+  uint64_t op_id;
+
+  GNUNET_assert (sizeof (struct GNUNET_TESTBED_PeerCreateSuccessEventMessage) ==
+                 ntohs (msg->header.size));
+  op_id = GNUNET_ntohll (msg->operation_id);
+  if (NULL == (opc = find_opc (c, op_id)))
+  {
+    LOG_DEBUG ("Operation context for PeerCreateSuccessEvent not found\n");
+    return GNUNET_YES;
+  }
+  if (OP_FORWARDED == opc->type)
+  {
+    handle_forwarded_operation_msg (c, opc,
+                                   (const struct GNUNET_MessageHeader *) msg);
+    return GNUNET_YES;
+  }
+  GNUNET_assert (OP_PEER_CREATE == opc->type);
+  GNUNET_assert (NULL != opc->data);
+  data = opc->data;
+  GNUNET_assert (NULL != data->peer);
+  peer = data->peer;
+  GNUNET_assert (peer->unique_id == ntohl (msg->peer_id));
+  peer->state = PS_CREATED;
+  cb = data->cb;
+  cls = data->cls;
+  GNUNET_free (opc->data);
+  GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  opc->state = OPC_STATE_FINISHED;
+  if (NULL != cb)
+    cb (cls, peer, NULL);
+  return GNUNET_YES;
+}
+
+
+/**
+ * Handler for GNUNET_MESSAGE_TYPE_TESTBED_PEEREVENT message from
+ * controller (testbed service)
+ *
+ * @param c the controller handler
+ * @param msg message received
+ * @return GNUNET_YES if we can continue receiving from service; GNUNET_NO if
+ *           not
+ */
+static int
+handle_peer_event (struct GNUNET_TESTBED_Controller *c,
+                   const struct GNUNET_TESTBED_PeerEventMessage *msg)
+{
+  struct OperationContext *opc;
+  struct GNUNET_TESTBED_Peer *peer;
+  struct PeerEventData *data;
+  GNUNET_TESTBED_PeerChurnCallback pcc;
+  void *pcc_cls;
+  struct GNUNET_TESTBED_EventInformation event;
+  uint64_t op_id;
+
+  GNUNET_assert (sizeof (struct GNUNET_TESTBED_PeerEventMessage) ==
+                 ntohs (msg->header.size));
+  op_id = GNUNET_ntohll (msg->operation_id);
+  if (NULL == (opc = find_opc (c, op_id)))
   {
     LOG_DEBUG ("Operation not found\n");
     return GNUNET_YES;
   }
-  event = NULL;
-  if (0 != (c->event_mask & (1L << GNUNET_TESTBED_ET_OPERATION_FINISHED)))
-    event = GNUNET_malloc (sizeof (struct GNUNET_TESTBED_EventInformation));
-  if (NULL != event)
-    event->type = GNUNET_TESTBED_ET_OPERATION_FINISHED; 
-  switch (op->type)
+  if (OP_FORWARDED == opc->type)
+  {
+    handle_forwarded_operation_msg (c, opc,
+                                   (const struct GNUNET_MessageHeader *) msg);
+    return GNUNET_YES;
+  }
+  GNUNET_assert ((OP_PEER_START == opc->type) || (OP_PEER_STOP == opc->type));
+  data = opc->data;
+  GNUNET_assert (NULL != data);
+  peer = data->peer;
+  GNUNET_assert (NULL != peer);
+  event.type = (enum GNUNET_TESTBED_EventType) ntohl (msg->event_type);
+  switch (event.type)
+  {
+  case GNUNET_TESTBED_ET_PEER_START:
+    peer->state = PS_STARTED;
+    event.details.peer_start.host = peer->host;
+    event.details.peer_start.peer = peer;
+    break;
+  case GNUNET_TESTBED_ET_PEER_STOP:
+    peer->state = PS_STOPPED;
+    event.details.peer_stop.peer = peer;
+    break;
+  default:
+    GNUNET_assert (0);          /* We should never reach this state */
+  }
+  pcc = data->pcc;
+  pcc_cls = data->pcc_cls;
+  GNUNET_free (data);
+  GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  opc->state = OPC_STATE_FINISHED;
+  if (0 !=
+      ((GNUNET_TESTBED_ET_PEER_START | GNUNET_TESTBED_ET_PEER_STOP) &
+       c->event_mask))
+  {
+    if (NULL != c->cc)
+      c->cc (c->cc_cls, &event);
+  }
+  if (NULL != pcc)
+    pcc (pcc_cls, NULL);
+  return GNUNET_YES;
+}
+
+
+/**
+ * Handler for GNUNET_MESSAGE_TYPE_TESTBED_PEERCONEVENT message from
+ * controller (testbed service)
+ *
+ * @param c the controller handler
+ * @param msg message received
+ * @return GNUNET_YES if we can continue receiving from service; GNUNET_NO if
+ *           not
+ */
+static int
+handle_peer_conevent (struct GNUNET_TESTBED_Controller *c,
+                      const struct GNUNET_TESTBED_ConnectionEventMessage *msg)
+{
+  struct OperationContext *opc;
+  struct OverlayConnectData *data;
+  GNUNET_TESTBED_OperationCompletionCallback cb;
+  void *cb_cls;
+  struct GNUNET_TESTBED_EventInformation event;
+  uint64_t op_id;
+
+  op_id = GNUNET_ntohll (msg->operation_id);
+  if (NULL == (opc = find_opc (c, op_id)))
+  {
+    LOG_DEBUG ("Operation not found\n");
+    return GNUNET_YES;
+  }
+  if (OP_FORWARDED == opc->type)
+  {
+    handle_forwarded_operation_msg (c, opc,
+                                   (const struct GNUNET_MessageHeader *) msg);
+    return GNUNET_YES;
+  }
+  GNUNET_assert (OP_OVERLAY_CONNECT == opc->type);
+  data = opc->data;
+  GNUNET_assert (NULL != data);
+  GNUNET_assert ((ntohl (msg->peer1) == data->p1->unique_id) &&
+                 (ntohl (msg->peer2) == data->p2->unique_id));
+  event.type = (enum GNUNET_TESTBED_EventType) ntohl (msg->event_type);
+  switch (event.type)
+  {
+  case GNUNET_TESTBED_ET_CONNECT:
+    event.details.peer_connect.peer1 = data->p1;
+    event.details.peer_connect.peer2 = data->p2;
+    break;
+  case GNUNET_TESTBED_ET_DISCONNECT:
+    GNUNET_assert (0);          /* FIXME: implement */
+    break;
+  default:
+    GNUNET_assert (0);          /* Should never reach here */
+    break;
+  }
+  cb = data->cb;
+  cb_cls = data->cb_cls;
+  GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  opc->state = OPC_STATE_FINISHED;
+  GNUNET_free (data);
+  if (0 !=
+      ((GNUNET_TESTBED_ET_CONNECT | GNUNET_TESTBED_ET_DISCONNECT) &
+       c->event_mask))
+  {
+    if (NULL != c->cc)
+      c->cc (c->cc_cls, &event);
+  }
+  if (NULL != cb)
+    cb (cb_cls, opc->op, NULL);
+  return GNUNET_YES;
+}
+
+
+/**
+ * Handler for GNUNET_MESSAGE_TYPE_TESTBED_PEERCONFIG message from
+ * controller (testbed service)
+ *
+ * @param c the controller handler
+ * @param msg message received
+ * @return GNUNET_YES if we can continue receiving from service; GNUNET_NO if
+ *           not
+ */
+static int
+handle_peer_config (struct GNUNET_TESTBED_Controller *c,
+                    const struct
+                    GNUNET_TESTBED_PeerConfigurationInformationMessage *msg)
+{
+  struct OperationContext *opc;
+  struct GNUNET_TESTBED_Peer *peer;
+  struct PeerInfoData *data;
+  struct GNUNET_TESTBED_PeerInformation *pinfo;
+  GNUNET_TESTBED_PeerInfoCallback cb;
+  void *cb_cls;
+  uint64_t op_id;
+
+  op_id = GNUNET_ntohll (msg->operation_id);
+  if (NULL == (opc = find_opc (c, op_id)))
+  {
+    LOG_DEBUG ("Operation not found\n");
+    return GNUNET_YES;
+  }
+  if (OP_FORWARDED == opc->type)
+  {
+    handle_forwarded_operation_msg (c, opc,
+                                   (const struct GNUNET_MessageHeader *) msg);
+    return GNUNET_YES;
+  }
+  data = opc->data;
+  GNUNET_assert (NULL != data);
+  peer = data->peer;
+  GNUNET_assert (NULL != peer);
+  GNUNET_assert (ntohl (msg->peer_id) == peer->unique_id);
+  pinfo = GNUNET_malloc (sizeof (struct GNUNET_TESTBED_PeerInformation));
+  pinfo->pit = data->pit;
+  cb = data->cb;
+  cb_cls = data->cb_cls;
+  GNUNET_free (data);
+  opc->data = NULL;
+  switch (pinfo->pit)
+  {
+  case GNUNET_TESTBED_PIT_IDENTITY:
+    pinfo->result.id = GNUNET_malloc (sizeof (struct GNUNET_PeerIdentity));
+    (void) memcpy (pinfo->result.id, &msg->peer_identity,
+                  sizeof (struct GNUNET_PeerIdentity));
+    break;
+  case GNUNET_TESTBED_PIT_CONFIGURATION:
+    pinfo->result.cfg =        /* Freed in oprelease_peer_getinfo */
+       GNUNET_TESTBED_extract_config_ (&msg->header);
+    break;
+  case GNUNET_TESTBED_PIT_GENERIC:
+    GNUNET_assert (0);          /* never reach here */
+    break;
+  }
+  opc->data = pinfo;
+  GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  opc->state = OPC_STATE_FINISHED;
+  if (NULL != cb)
+    cb (cb_cls, opc->op, pinfo, NULL);
+  return GNUNET_YES;
+}
+
+
+/**
+ * Handler for GNUNET_MESSAGE_TYPE_TESTBED_OPERATIONFAILEVENT message from
+ * controller (testbed service)
+ *
+ * @param c the controller handler
+ * @param msg message received
+ * @return GNUNET_YES if we can continue receiving from service; GNUNET_NO if
+ *           not
+ */
+static int
+handle_op_fail_event (struct GNUNET_TESTBED_Controller *c,
+                      const struct GNUNET_TESTBED_OperationFailureEventMessage
+                      *msg)
+{
+  struct OperationContext *opc;
+  const char *emsg;
+  uint64_t op_id;
+  struct GNUNET_TESTBED_EventInformation event;
+
+  op_id = GNUNET_ntohll (msg->operation_id);
+  if (NULL == (opc = find_opc (c, op_id)))
   {
+    LOG_DEBUG ("Operation not found\n");
+    return GNUNET_YES;
+  }
+  GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  if (OP_FORWARDED == opc->type)
+  {
+    handle_forwarded_operation_msg (c, opc,
+                                   (const struct GNUNET_MessageHeader *) msg);
+    return GNUNET_YES;
+  }
+  opc->state = OPC_STATE_FINISHED;
+  emsg = GNUNET_TESTBED_parse_error_string_ (msg);
+  if (NULL == emsg)
+    emsg = "Unknown error";
+  if (OP_PEER_INFO == opc->type)
+  {
+    struct PeerInfoData *data;
+    data = opc->data;
+    if (NULL != data->cb)
+      data->cb (data->cb_cls, opc->op, NULL, emsg);
+    GNUNET_free (data);
+    return GNUNET_YES;  /* We do not call controller callback for peer info */
+  }
+  if ((0 != (GNUNET_TESTBED_ET_OPERATION_FINISHED & c->event_mask)) &&
+      (NULL != c->cc))
+  {
+    event.type = GNUNET_TESTBED_ET_OPERATION_FINISHED;
+    event.details.operation_finished.operation = opc->op;
+    event.details.operation_finished.op_cls = opc->op_cls;
+    event.details.operation_finished.emsg = emsg;
+    event.details.operation_finished.generic = NULL;
+    c->cc (c->cc_cls, &event);
+  }
+  switch (opc->type)
+  {
+  case OP_PEER_CREATE:
+    {
+      struct PeerCreateData *data;      
+      data = opc->data;
+      GNUNET_free (data->peer);
+      if (NULL != data->cb)
+        data->cb (data->cls, NULL, emsg);
+      GNUNET_free (data);      
+    }
+    break;
+  case OP_PEER_START:
+  case OP_PEER_STOP:
+    {
+      struct PeerEventData *data;
+      data = opc->data;
+      if (NULL != data->pcc)
+        data->pcc (data->pcc_cls, emsg);
+      GNUNET_free (data);
+    }
+    break;
   case OP_PEER_DESTROY:
+    break;
+  case OP_PEER_INFO:
+    GNUNET_assert (0);
+  case OP_OVERLAY_CONNECT:
     {
-      struct PeerDestroyData *data;
-      
-      if (NULL != event)
+      struct OverlayConnectData *data;
+      data = opc->data;
+      if (NULL != data->cb)
+        data->cb (data->cb_cls, opc->op, emsg);
+      GNUNET_free (data);
+    }
+    break;
+  case OP_FORWARDED:
+    GNUNET_assert (0);
+  case OP_LINK_CONTROLLERS:     /* No secondary callback */
+    break;
+  default:
+    GNUNET_break (0);
+  }  
+  return GNUNET_YES;
+}
+
+
+/**
+ * Function to build GET_SLAVE_CONFIG message
+ *
+ * @param op_id the id this message should contain in its operation id field
+ * @param slave_id the id this message should contain in its slave id field
+ * @return newly allocated SlaveGetConfigurationMessage
+ */
+static struct GNUNET_TESTBED_SlaveGetConfigurationMessage *
+GNUNET_TESTBED_generate_slavegetconfig_msg_ (uint64_t op_id, uint32_t slave_id)
+{
+  struct GNUNET_TESTBED_SlaveGetConfigurationMessage *msg;
+  uint16_t msize;
+  
+  msize = sizeof (struct GNUNET_TESTBED_SlaveGetConfigurationMessage);
+  msg = GNUNET_malloc (msize);
+  msg->header.size = htons (msize);
+  msg->header.type = htons (GNUNET_MESSAGE_TYPE_TESTBED_GETSLAVECONFIG);
+  msg->operation_id = GNUNET_htonll (op_id);
+  msg->slave_id = htonl (slave_id);
+  return msg;
+}
+
+
+/**
+ * Handler for GNUNET_MESSAGE_TYPE_TESTBED_SLAVECONFIG message from controller
+ * (testbed service)
+ *
+ * @param c the controller handler
+ * @param msg message received
+ * @return GNUNET_YES if we can continue receiving from service; GNUNET_NO if
+ *           not
+ */
+static int
+handle_slave_config (struct GNUNET_TESTBED_Controller *c,
+                    const struct GNUNET_TESTBED_SlaveConfiguration * msg)
+{
+  struct OperationContext *opc;
+  uint64_t op_id;
+  struct GNUNET_TESTBED_EventInformation event;  
+
+  op_id = GNUNET_ntohll (msg->operation_id);
+  if (NULL == (opc = find_opc (c, op_id)))
+  {
+    LOG_DEBUG ("Operation not found\n");
+    return GNUNET_YES;
+  }
+  if (OP_GET_SLAVE_CONFIG != opc->type)
+  {
+    GNUNET_break (0);
+    return GNUNET_YES;
+  }
+  GNUNET_free (opc->data);
+  opc->data = NULL;
+  opc->state = OPC_STATE_FINISHED;
+  GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  if ((0 != (GNUNET_TESTBED_ET_OPERATION_FINISHED & c->event_mask)) &&
+      (NULL != c->cc))
+  {
+    opc->data = GNUNET_TESTBED_extract_config_ (&msg->header);
+    event.type = GNUNET_TESTBED_ET_OPERATION_FINISHED;   
+    event.details.operation_finished.generic = opc->data;
+    event.details.operation_finished.operation = opc->op;
+    event.details.operation_finished.op_cls = opc->op_cls;
+    event.details.operation_finished.emsg = NULL;
+    c->cc (c->cc_cls, &event);
+  }
+  return GNUNET_YES;
+}
+
+
+/**
+ * Callback to check status for suboperations generated during overlay connect.
+ *
+ * @param cls the OverlayConnectData
+ * @param message the reply message to the suboperation
+ */
+static void
+overlay_connect_ondemand_handler (void *cls,
+                                  const struct GNUNET_MessageHeader *message)
+{
+  struct OverlayConnectData *oc_data = cls;
+
+  switch (oc_data->state)
+  {
+  case OCD_CFG_ACQUIRE:
+    {
+      struct GNUNET_CONFIGURATION_Handle *cfg;
+
+      if (GNUNET_MESSAGE_TYPE_TESTBED_SLAVECONFIG != ntohs (message->type))
       {
-        event->details.operation_finished.operation = op;
-        event->details.operation_finished.op_cls = NULL;
-        event->details.operation_finished.emsg = NULL;
-        event->details.operation_finished.pit = GNUNET_TESTBED_PIT_GENERIC;
-        event->details.operation_finished.op_result.generic = NULL;
+        GNUNET_break (0);       /* treat operation as failed */
       }
-      data = (struct PeerDestroyData *) op->data;
-      if (NULL != data->peer->details)
+      cfg = GNUNET_TESTBED_extract_config_ (message);
+      if (NULL == cfg)
       {
-        if (NULL != data->peer->details->cfg)
-          GNUNET_CONFIGURATION_destroy (data->peer->details->cfg);
-        //PEER_DETAILS
+        GNUNET_break (0);       /* failed operation */
       }
-      GNUNET_free (data->peer);
-      GNUNET_free (data);
-      //PEERDESTROYDATA
+      oc_data->state = OCD_LINK_CONTROLLERS;
     }
-    break;
   default:
-    GNUNET_break (0);
+    GNUNET_assert (0);
   }
-  if (NULL != event)
+}
+
+
+/**
+ * Handler for GNUNET_MESSAGE_TYPE_TESTBED_NEEDCONTROLLERCONFIG message from
+ * controller (testbed service)
+ *
+ * @param c the controller handler
+ * @param msg message received
+ * @return GNUNET_YES if we can continue receiving from service; GNUNET_NO if
+ *           not
+ */
+static int
+handle_need_controller_config (struct GNUNET_TESTBED_Controller *c,
+                               const struct GNUNET_TESTBED_NeedControllerConfig * msg)
+{
+  struct OperationContext *opc;
+  struct OverlayConnectData *oc_data;
+  uint64_t op_id;
+
+  op_id = GNUNET_ntohll (msg->operation_id);
+  if (NULL == (opc = find_opc (c, op_id)))
   {
-    if (NULL != c->cc)
-      c->cc (c->cc_cls, event);
-    GNUNET_free (event);
+    LOG_DEBUG ("Operation not found\n");
+    return GNUNET_YES;
   }
-  GNUNET_CONTAINER_DLL_remove (c->op_head, c->op_tail, op);
-  GNUNET_free (op);
-  return GNUNET_YES;  
+  if (OP_FORWARDED == opc->type)
+  {
+    handle_forwarded_operation_msg (c, opc,
+                                    (const struct GNUNET_MessageHeader *) msg);
+    return GNUNET_YES;
+  }
+  GNUNET_assert (OP_OVERLAY_CONNECT == opc->type);
+  oc_data = opc->data;
+  /* FIXME: Should spawn operations to:
+     1. Acquire configuration of peer2's controller,
+     2. link peer1's controller to peer2's controller
+     3. ask them to attempt overlay connect on peer1 and peer2 again */
+  switch (oc_data->state)
+  {
+  case OCD_INIT:
+    {
+      struct GNUNET_TESTBED_SlaveGetConfigurationMessage *get_cfg_msg;
+      uint64_t sub_op_id;
+      
+      GNUNET_assert (NULL == oc_data->sub_opc);
+      sub_op_id = GNUNET_TESTBED_get_next_op_id (oc_data->p1->controller);
+      get_cfg_msg = 
+          GNUNET_TESTBED_generate_slavegetconfig_msg_ 
+          (sub_op_id, GNUNET_TESTBED_host_get_id_ (oc_data->p2->host));
+      oc_data->state = OCD_CFG_ACQUIRE;
+      oc_data->sub_opc =
+          GNUNET_TESTBED_forward_operation_msg_ (oc_data->p1->controller,
+                                                 sub_op_id, &get_cfg_msg->header,
+                                                 overlay_connect_ondemand_handler,
+                                                 oc_data);
+    }
+    break;
+  default:
+    GNUNET_assert (0);
+  }
+  return GNUNET_YES;
 }
 
 
@@ -291,11 +973,12 @@ handle_opsuccess (struct GNUNET_TESTBED_Controller *c,
  * @param cls the controller handler
  * @param msg message received, NULL on timeout or fatal error
  */
-static void 
+static void
 message_handler (void *cls, const struct GNUNET_MessageHeader *msg)
 {
-  struct GNUNET_TESTBED_Controller *c = cls;  
+  struct GNUNET_TESTBED_Controller *c = cls;
   int status;
+  uint16_t msize;
 
   c->in_receive = GNUNET_NO;
   /* FIXME: Add checks for message integrity */
@@ -305,27 +988,95 @@ message_handler (void *cls, const struct GNUNET_MessageHeader *msg)
     return;
   }
   status = GNUNET_OK;
+  msize = ntohs (msg->size);
   switch (ntohs (msg->type))
   {
   case GNUNET_MESSAGE_TYPE_TESTBED_ADDHOSTCONFIRM:
+    GNUNET_assert (msize >=
+                   sizeof (struct GNUNET_TESTBED_HostConfirmedMessage));
     status =
-      handle_addhostconfirm (c, (const struct
-                                 GNUNET_TESTBED_HostConfirmedMessage *) msg);
+        handle_addhostconfirm (c,
+                               (const struct GNUNET_TESTBED_HostConfirmedMessage
+                                *) msg);
     break;
   case GNUNET_MESSAGE_TYPE_TESTBED_GENERICOPSUCCESS:
+    GNUNET_assert (msize ==
+                   sizeof (struct
+                           GNUNET_TESTBED_GenericOperationSuccessEventMessage));
+    status =
+        handle_opsuccess (c,
+                          (const struct
+                           GNUNET_TESTBED_GenericOperationSuccessEventMessage *)
+                          msg);
+    break;
+  case GNUNET_MESSAGE_TYPE_TESTBED_PEERCREATESUCCESS:
+    GNUNET_assert (msize ==
+                   sizeof (struct
+                           GNUNET_TESTBED_PeerCreateSuccessEventMessage));
+    status =
+        handle_peer_create_success (c,
+                                    (const struct
+                                     GNUNET_TESTBED_PeerCreateSuccessEventMessage
+                                     *) msg);
+    break;
+  case GNUNET_MESSAGE_TYPE_TESTBED_PEEREVENT:
+    GNUNET_assert (msize == sizeof (struct GNUNET_TESTBED_PeerEventMessage));
+    status =
+        handle_peer_event (c,
+                           (const struct GNUNET_TESTBED_PeerEventMessage *)
+                           msg);
+
+    break;
+  case GNUNET_MESSAGE_TYPE_TESTBED_PEERCONFIG:
+    GNUNET_assert (msize >=
+                   sizeof (struct
+                           GNUNET_TESTBED_PeerConfigurationInformationMessage));
+    status =
+        handle_peer_config (c,
+                            (const struct
+                             GNUNET_TESTBED_PeerConfigurationInformationMessage
+                             *) msg);
+    break;
+  case GNUNET_MESSAGE_TYPE_TESTBED_PEERCONEVENT:
+    GNUNET_assert (msize ==
+                   sizeof (struct GNUNET_TESTBED_ConnectionEventMessage));
+    status =
+        handle_peer_conevent (c,
+                              (const struct
+                               GNUNET_TESTBED_ConnectionEventMessage *) msg);
+    break;
+  case GNUNET_MESSAGE_TYPE_TESTBED_OPERATIONFAILEVENT:
+    GNUNET_assert (msize >=
+                   sizeof (struct GNUNET_TESTBED_OperationFailureEventMessage));
     status =
-      handle_opsuccess (c, (const struct
-                            GNUNET_TESTBED_GenericOperationSuccessEventMessage
-                            *) msg);
+        handle_op_fail_event (c,
+                              (const struct
+                               GNUNET_TESTBED_OperationFailureEventMessage *)
+                              msg);
+    break;
+  case GNUNET_MESSAGE_TYPE_TESTBED_SLAVECONFIG:
+    GNUNET_assert (msize >
+                  sizeof (struct GNUNET_TESTBED_SlaveConfiguration));
+    status = 
+       handle_slave_config (c, (const struct 
+                                GNUNET_TESTBED_SlaveConfiguration *) msg);
+    break;
+  case GNUNET_MESSAGE_TYPE_TESTBED_NEEDCONTROLLERCONFIG:
+    GNUNET_assert (msize == sizeof (struct
+                                    GNUNET_TESTBED_NeedControllerConfig));
+    status = 
+        handle_need_controller_config (c, (const struct
+                                           GNUNET_TESTBED_NeedControllerConfig
+                                           *) msg);
     break;
   default:
-    GNUNET_break (0);
+    GNUNET_assert (0);
   }
   if ((GNUNET_OK == status) && (GNUNET_NO == c->in_receive))
   {
     c->in_receive = GNUNET_YES;
     GNUNET_CLIENT_receive (c->client, &message_handler, c,
-                           GNUNET_TIME_UNIT_FOREVER_REL);    
+                           GNUNET_TIME_UNIT_FOREVER_REL);
   }
 }
 
@@ -343,193 +1094,445 @@ message_handler (void *cls, const struct GNUNET_MessageHeader *msg)
 static size_t
 transmit_ready_notify (void *cls, size_t size, void *buf)
 {
-  struct GNUNET_TESTBED_Controller *c = cls;
-  struct MessageQueue *mq_entry;
-
-  c->th = NULL;
-  mq_entry = c->mq_head;
-  GNUNET_assert (NULL != mq_entry);
-  if ((0 == size) && (NULL == buf)) /* Timeout */
-  {
-    LOG_DEBUG ("Message sending timed out -- retrying\n");
-    c->th =
-      GNUNET_CLIENT_notify_transmit_ready (c->client,
-                                           ntohs (mq_entry->msg->size),
-                                           TIMEOUT_REL,
-                                           GNUNET_YES, &transmit_ready_notify,
-                                           c);
-    return 0;
-  }
-  GNUNET_assert (ntohs (mq_entry->msg->size) <= size);
-  size = ntohs (mq_entry->msg->size);  
-  memcpy (buf, mq_entry->msg, size);
-  LOG_DEBUG ("Message of type: %u and size: %u sent\n",
-            ntohs (mq_entry->msg->type), size);
-  GNUNET_free (mq_entry->msg);
-  GNUNET_CONTAINER_DLL_remove (c->mq_head, c->mq_tail, mq_entry);
-  GNUNET_free (mq_entry);
-  mq_entry = c->mq_head;
-  if (NULL != mq_entry)
-    c->th = 
-      GNUNET_CLIENT_notify_transmit_ready (c->client,
-                                           ntohs (mq_entry->msg->size),
-                                           TIMEOUT_REL,
-                                           GNUNET_YES, &transmit_ready_notify,
-                                           c);
-  if (GNUNET_NO == c->in_receive)
-  {
-    c->in_receive = GNUNET_YES;
-    GNUNET_CLIENT_receive (c->client, &message_handler, c,
-                          GNUNET_TIME_UNIT_FOREVER_REL);
-  }
-  return size;
+  struct GNUNET_TESTBED_Controller *c = cls;
+  struct MessageQueue *mq_entry;
+
+  c->th = NULL;
+  mq_entry = c->mq_head;
+  GNUNET_assert (NULL != mq_entry);
+  if ((0 == size) && (NULL == buf))     /* Timeout */
+  {
+    LOG_DEBUG ("Message sending timed out -- retrying\n");
+    c->th =
+        GNUNET_CLIENT_notify_transmit_ready (c->client,
+                                             ntohs (mq_entry->msg->size),
+                                             TIMEOUT_REL, GNUNET_YES,
+                                             &transmit_ready_notify, c);
+    return 0;
+  }
+  GNUNET_assert (ntohs (mq_entry->msg->size) <= size);
+  size = ntohs (mq_entry->msg->size);
+  memcpy (buf, mq_entry->msg, size);
+  LOG_DEBUG ("Message of type: %u and size: %u sent\n",
+             ntohs (mq_entry->msg->type), size);
+  GNUNET_free (mq_entry->msg);
+  GNUNET_CONTAINER_DLL_remove (c->mq_head, c->mq_tail, mq_entry);
+  GNUNET_free (mq_entry);
+  mq_entry = c->mq_head;
+  if (NULL != mq_entry)
+    c->th =
+        GNUNET_CLIENT_notify_transmit_ready (c->client,
+                                             ntohs (mq_entry->msg->size),
+                                             TIMEOUT_REL, GNUNET_YES,
+                                             &transmit_ready_notify, c);
+  if (GNUNET_NO == c->in_receive)
+  {
+    c->in_receive = GNUNET_YES;
+    GNUNET_CLIENT_receive (c->client, &message_handler, c,
+                           GNUNET_TIME_UNIT_FOREVER_REL);
+  }
+  return size;
+}
+
+
+/**
+ * Queues a message in send queue for sending to the service
+ *
+ * @param controller the handle to the controller
+ * @param msg the message to queue
+ */
+void
+GNUNET_TESTBED_queue_message_ (struct GNUNET_TESTBED_Controller *controller,
+                               struct GNUNET_MessageHeader *msg)
+{
+  struct MessageQueue *mq_entry;
+  uint16_t type;
+  uint16_t size;
+
+  type = ntohs (msg->type);
+  size = ntohs (msg->size);
+  GNUNET_assert ((GNUNET_MESSAGE_TYPE_TESTBED_INIT <= type) &&
+                 (GNUNET_MESSAGE_TYPE_TESTBED_MAX > type));
+  mq_entry = GNUNET_malloc (sizeof (struct MessageQueue));
+  mq_entry->msg = msg;
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Queueing message of type %u, size %u for sending\n", type,
+       ntohs (msg->size));
+  GNUNET_CONTAINER_DLL_insert_tail (controller->mq_head, controller->mq_tail,
+                                    mq_entry);
+  if (NULL == controller->th)
+    controller->th =
+        GNUNET_CLIENT_notify_transmit_ready (controller->client, size,
+                                             TIMEOUT_REL, GNUNET_YES,
+                                             &transmit_ready_notify,
+                                             controller);
+}
+
+
+/**
+ * Sends the given message as an operation. The given callback is called when a
+ * reply for the operation is available.  Call
+ * GNUNET_TESTBED_forward_operation_msg_cancel_() to cleanup the returned
+ * operation context if the cc hasn't been called
+ *
+ * @param controller the controller to which the message has to be sent
+ * @param operation_id the operation id of the message
+ * @param msg the message to send
+ * @param cc the callback to call when reply is available
+ * @param cc_cls the closure for the above callback
+ * @return the operation context which can be used to cancel the forwarded
+ *           operation
+ */
+struct OperationContext *
+GNUNET_TESTBED_forward_operation_msg_ (struct GNUNET_TESTBED_Controller
+                                       *controller, uint64_t operation_id,
+                                       const struct GNUNET_MessageHeader *msg,
+                                       GNUNET_CLIENT_MessageHandler cc,
+                                       void *cc_cls)
+{
+  struct OperationContext *opc;
+  struct ForwardedOperationData *data;
+  struct GNUNET_MessageHeader *dup_msg;
+  uint16_t msize;
+
+  data = GNUNET_malloc (sizeof (struct ForwardedOperationData));
+  data->cc = cc;
+  data->cc_cls = cc_cls;
+  opc = GNUNET_malloc (sizeof (struct OperationContext));
+  opc->c = controller;
+  opc->type = OP_FORWARDED;
+  opc->data = data;
+  opc->id = operation_id;
+  msize = ntohs (msg->size);
+  dup_msg = GNUNET_malloc (msize);
+  (void) memcpy (dup_msg, msg, msize);
+  GNUNET_TESTBED_queue_message_ (opc->c, dup_msg);
+  GNUNET_CONTAINER_DLL_insert_tail (controller->ocq_head, controller->ocq_tail,
+                                    opc);
+  return opc;
+}
+
+
+/**
+ * Function to cancel an operation created by simply forwarding an operation
+ * message.
+ *
+ * @param opc the operation context from GNUNET_TESTBED_forward_operation_msg_()
+ */
+void
+GNUNET_TESTBED_forward_operation_msg_cancel_ (struct OperationContext *opc)
+{
+  GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  GNUNET_free (opc->data);
+  GNUNET_free (opc);
+}
+
+
+/**
+ * Functions with this signature are called whenever a
+ * complete message is received by the tokenizer.
+ *
+ * Do not call GNUNET_SERVER_mst_destroy in callback
+ *
+ * @param cls closure
+ * @param client identification of the client
+ * @param message the actual message
+ *
+ * @return GNUNET_OK on success, GNUNET_SYSERR to stop further processing
+ */
+static int
+helper_mst (void *cls, void *client, const struct GNUNET_MessageHeader *message)
+{
+  struct GNUNET_TESTBED_ControllerProc *cp = cls;
+  const struct GNUNET_TESTBED_HelperReply *msg;
+  const char *hostname;
+  char *config;
+  uLongf config_size;
+  uLongf xconfig_size;
+
+  msg = (const struct GNUNET_TESTBED_HelperReply *) message;
+  GNUNET_assert (sizeof (struct GNUNET_TESTBED_HelperReply) <
+                 ntohs (msg->header.size));
+  GNUNET_assert (GNUNET_MESSAGE_TYPE_TESTBED_HELPER_REPLY ==
+                 ntohs (msg->header.type));
+  config_size = (uLongf) ntohs (msg->config_size);
+  xconfig_size =
+      (uLongf) (ntohs (msg->header.size) -
+                sizeof (struct GNUNET_TESTBED_HelperReply));
+  config = GNUNET_malloc (config_size);
+  GNUNET_assert (Z_OK ==
+                 uncompress ((Bytef *) config, &config_size,
+                             (const Bytef *) &msg[1], xconfig_size));
+  GNUNET_assert (NULL == cp->cfg);
+  cp->cfg = GNUNET_CONFIGURATION_create ();
+  GNUNET_assert (GNUNET_CONFIGURATION_deserialize
+                 (cp->cfg, config, config_size, GNUNET_NO));
+  GNUNET_free (config);
+  if ((NULL == cp->host) ||
+      (NULL == (hostname = GNUNET_TESTBED_host_get_hostname_ (cp->host))))
+    hostname = "localhost";
+  /* Change the hostname so that we can connect to it */
+  GNUNET_CONFIGURATION_set_value_string (cp->cfg, "testbed", "hostname",
+                                         hostname);
+  cp->cb (cp->cls, cp->cfg, GNUNET_OK);
+  return GNUNET_OK;
+}
+
+
+/**
+ * Continuation function from GNUNET_HELPER_send()
+ *
+ * @param cls closure
+ * @param result GNUNET_OK on success,
+ *               GNUNET_NO if helper process died
+ *               GNUNET_SYSERR during GNUNET_HELPER_stop
+ */
+static void
+clear_msg (void *cls, int result)
+{
+  struct GNUNET_TESTBED_ControllerProc *cp = cls;
+
+  GNUNET_assert (NULL != cp->shandle);
+  cp->shandle = NULL;
+  GNUNET_free (cp->msg);
+}
+
+
+/**
+ * Callback that will be called when the helper process dies. This is not called
+ * when the helper process is stoped using GNUNET_HELPER_stop()
+ *
+ * @param cls the closure from GNUNET_HELPER_start()
+ */
+static void
+helper_exp_cb (void *cls)
+{
+  struct GNUNET_TESTBED_ControllerProc *cp = cls;
+  GNUNET_TESTBED_ControllerStatusCallback cb;
+  void *cb_cls;
+
+  cb = cp->cb;
+  cb_cls = cp->cls;
+  cp->helper = NULL;
+  GNUNET_TESTBED_controller_stop (cp);
+  if (NULL != cb)
+    cb (cb_cls, NULL, GNUNET_SYSERR);
 }
 
 
 /**
- * Queues a message in send queue for sending to the service
+ * Function to call to start a link-controllers type operation once all queues
+ * the operation is part of declare that the operation can be activated.
  *
- * @param controller the handle to the controller
- * @param msg the message to queue
+ * @param cls the closure from GNUNET_TESTBED_operation_create_()
  */
-void
-GNUNET_TESTBED_queue_message (struct GNUNET_TESTBED_Controller *controller,
-                              struct GNUNET_MessageHeader *msg)
+static void
+opstart_link_controllers (void *cls)
 {
-  struct MessageQueue *mq_entry;
-  uint16_t type;
-  uint16_t size;
+  struct OperationContext *opc = cls;
+  struct ControllerLinkData *data;
+  struct GNUNET_TESTBED_ControllerLinkMessage *msg;
 
-  type = ntohs (msg->type);
-  size = ntohs (msg->size);
-  GNUNET_assert ((GNUNET_MESSAGE_TYPE_TESTBED_INIT <= type) &&
-                 (GNUNET_MESSAGE_TYPE_TESTBED_MAX > type));                 
-  mq_entry = GNUNET_malloc (sizeof (struct MessageQueue));
-  mq_entry->msg = msg;
-  LOG (GNUNET_ERROR_TYPE_DEBUG,
-       "Queueing message of type %u, size %u for sending\n", type,
-       ntohs (msg->size));
-  GNUNET_CONTAINER_DLL_insert_tail (controller->mq_head, controller->mq_tail,
-                                    mq_entry);
-  if (NULL == controller->th)
-    controller->th = 
-      GNUNET_CLIENT_notify_transmit_ready (controller->client, size,
-                                           TIMEOUT_REL,
-                                           GNUNET_YES, &transmit_ready_notify,
-                                           controller);
+  GNUNET_assert (NULL != opc->data);
+  data = opc->data;
+  msg = data->msg;
+  data->msg = NULL;
+  opc->state = OPC_STATE_STARTED;
+  GNUNET_CONTAINER_DLL_insert_tail (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  GNUNET_TESTBED_queue_message_ (opc->c, &msg->header);
 }
 
 
 /**
- * Handle for controller process
+ * Callback which will be called when link-controllers type operation is released
+ *
+ * @param cls the closure from GNUNET_TESTBED_operation_create_()
  */
-struct GNUNET_TESTBED_ControllerProc
+static void
+oprelease_link_controllers (void *cls)
 {
-  /**
-   * The helper handle
-   */
-  struct GNUNET_TESTBED_HelperHandle *helper;
+  struct OperationContext *opc = cls;
+  struct ControllerLinkData *data;
 
-};
+  data = opc->data;
+  switch (opc->state)
+  {
+  case OPC_STATE_INIT:
+    GNUNET_free (data->msg);
+    break;
+  case OPC_STATE_STARTED:
+    GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+    break;
+  case OPC_STATE_FINISHED:
+    break;
+  }
+  GNUNET_free_non_null (data);
+  GNUNET_free (opc);
+}
 
 
 /**
- * Context to use while starting a controller
+ * Function to be called when get slave config operation is ready
+ *
+ * @param cls the OperationContext of type OP_GET_SLAVE_CONFIG
  */
-struct ControllerStartContext
+static void
+opstart_get_slave_config (void *cls)
 {
-  /**
-   * The error callback
-   */
-  GNUNET_TESTBED_ControllerErrorCallback cec;
+  struct OperationContext *opc = cls;
+  struct GetSlaveConfigData *data;
+  struct GNUNET_TESTBED_SlaveGetConfigurationMessage *msg;
+
+  data = opc->data;
+  msg = GNUNET_TESTBED_generate_slavegetconfig_msg_ (opc->id, data->slave_id);
+  GNUNET_CONTAINER_DLL_insert_tail (opc->c->ocq_head, opc->c->ocq_tail, opc);
+  GNUNET_TESTBED_queue_message_ (opc->c, &msg->header);
+  opc->state = OPC_STATE_STARTED;
+}
 
-  /**
-   * Closure for the above callback
-   */
-  void *cec_cls;
 
-  /**
-   * error message if any
-   */
-  char *emsg;
-};
+/**
+ * Function to be called when get slave config operation is cancelled or finished
+ *
+ * @param cls the OperationContext of type OP_GET_SLAVE_CONFIG
+ */
+static void
+oprelease_get_slave_config (void *cls)
+{
+  struct OperationContext *opc = cls;
+
+  switch (opc->state)
+  {
+  case OPC_STATE_INIT:
+    GNUNET_free (opc->data);
+    break;
+  case OPC_STATE_STARTED:
+    GNUNET_free (opc->data);
+    GNUNET_CONTAINER_DLL_remove (opc->c->ocq_head, opc->c->ocq_tail, opc);
+    break;
+  case OPC_STATE_FINISHED:
+    if (NULL != opc->data)
+      GNUNET_CONFIGURATION_destroy (opc->data);
+    break;
+  }
+  GNUNET_free (opc);
+}
 
 
 /**
- * Starts a controller process at the host
+ * Starts a controller process at the host. FIXME: add controller start callback
+ * with the configuration with which the controller is started
  *
- * @param system used for reserving ports if host is NULL and to determine
- *               which 'host' to set as TRUSTED ('controller') when starting testbed remotely
- * @param host the host where the controller has to be started; NULL for localhost
- * @param cfg template configuration to use for the remote controller; will
- *            be modified to contain the actual host/port/unixpath used for
- *            the testbed service
- * @param cec function called if the contoller dies unexpectedly; will not be 
- *            invoked after GNUNET_TESTBED_controller_stop, if 'cec' was called,
- *            GNUNET_TESTBED_controller_stop must no longer be called; will
- *            never be called in the same task as 'GNUNET_TESTBED_controller_start'
- *            (synchronous errors will be signalled by returning NULL)
- * @param cec_cls closure for 'cec'
+ * @param controller_ip the ip address of the controller. Will be set as TRUSTED
+ *          host when starting testbed controller at host
+ * @param host the host where the controller has to be started; NULL for
+ *          localhost
+ * @param cfg template configuration to use for the remote controller; the
+ *          remote controller will be started with a slightly modified
+ *          configuration (port numbers, unix domain sockets and service home
+ *          values are changed as per TESTING library on the remote host)
+ * @param cb function called when the controller is successfully started or
+ *          dies unexpectedly; GNUNET_TESTBED_controller_stop shouldn't be
+ *          called if cb is called with GNUNET_SYSERR as status. Will never be
+ *          called in the same task as 'GNUNET_TESTBED_controller_start'
+ *          (synchronous errors will be signalled by returning NULL). This
+ *          parameter cannot be NULL.
+ * @param cls closure for above callbacks
  * @return the controller process handle, NULL on errors
  */
 struct GNUNET_TESTBED_ControllerProc *
-GNUNET_TESTBED_controller_start (struct GNUNET_TESTING_System *system,
-                                struct GNUNET_TESTBED_Host *host,
-                                struct GNUNET_CONFIGURATION_Handle *cfg,
-                                GNUNET_TESTBED_ControllerErrorCallback cec,
-                                void *cec_cls)
+GNUNET_TESTBED_controller_start (const char *controller_ip,
+                                 struct GNUNET_TESTBED_Host *host,
+                                 const struct GNUNET_CONFIGURATION_Handle *cfg,
+                                 GNUNET_TESTBED_ControllerStatusCallback cb,
+                                 void *cls)
 {
-  struct GNUNET_TESTBED_ControllerProc *cproc;
-  //struct ControllerStartContext *csc;
-  char *cfg_filename;
-
+  struct GNUNET_TESTBED_ControllerProc *cp;
+  struct GNUNET_TESTBED_HelperInit *msg;
+  const char *hostname;
+  static char *const binary_argv[] = {
+    HELPER_TESTBED_BINARY, NULL
+  };
+  
+  hostname = NULL;
+  cp = GNUNET_malloc (sizeof (struct GNUNET_TESTBED_ControllerProc));
   if ((NULL == host) || (0 == GNUNET_TESTBED_host_get_id_ (host)))
+    cp->helper =
+        GNUNET_HELPER_start (GNUNET_YES, HELPER_TESTBED_BINARY, binary_argv,
+                             &helper_mst, &helper_exp_cb, cp);
+  else
   {
-    if (GNUNET_OK != GNUNET_TESTING_configuration_create (system, cfg))
-      return NULL;
-    GNUNET_assert 
-      (GNUNET_OK == 
-       GNUNET_CONFIGURATION_get_value_string (cfg, "PATHS", "DEFAULTCONFIG",
-                                             &cfg_filename));
-    if (GNUNET_OK != GNUNET_CONFIGURATION_write (cfg, cfg_filename))
-    {
-      GNUNET_break (0);
-      return NULL;
-    }
-    char * const binary_argv[] = {
-      "gnunet-service-testbed",
-      "-c", cfg_filename,
-      NULL
-    };
-    cproc = GNUNET_malloc (sizeof (struct GNUNET_TESTBED_ControllerProc));
-    cproc->helper = GNUNET_TESTBED_host_run_ (host, binary_argv);
-    GNUNET_free (cfg_filename);
-    if (NULL == cproc->helper)
-    {
-      GNUNET_free (cproc);
-      return NULL;
-    }
+    char *remote_args[10];
+    unsigned int argp;
+    const char *username;
+
+    username = GNUNET_TESTBED_host_get_username_ (host);
+    hostname = GNUNET_TESTBED_host_get_hostname_ (host);
+    GNUNET_asprintf (&cp->port, "%u", GNUNET_TESTBED_host_get_ssh_port_ (host));
+    if (NULL == username)
+      GNUNET_asprintf (&cp->dst, "%s", hostname);
+    else
+      GNUNET_asprintf (&cp->dst, "%s@%s", username, hostname);
+    LOG_DEBUG ("Starting SSH to destination %s\n", cp->dst);
+    argp = 0;
+    remote_args[argp++] = "ssh";
+    remote_args[argp++] = "-p";
+    remote_args[argp++] = cp->port;
+    remote_args[argp++] = "-o";
+    remote_args[argp++] = "BatchMode=yes";
+    remote_args[argp++] = "-o";
+    remote_args[argp++] = "NoHostAuthenticationForLocalhost=yes";
+    remote_args[argp++] = cp->dst;
+    remote_args[argp++] = HELPER_TESTBED_BINARY_SSH;
+    remote_args[argp++] = NULL;
+    GNUNET_assert (argp == 10);
+    cp->helper =
+        GNUNET_HELPER_start (GNUNET_NO, "ssh", remote_args, &helper_mst,
+                             &helper_exp_cb, cp);
   }
-  else
+  if (NULL == cp->helper)
   {
-    GNUNET_break (0);
+    GNUNET_free_non_null (cp->port);
+    GNUNET_free_non_null (cp->dst);
+    GNUNET_free (cp);
     return NULL;
   }
-  return cproc;
+  cp->host = host;
+  cp->cb = cb;
+  cp->cls = cls;
+  msg = GNUNET_TESTBED_create_helper_init_msg_ (controller_ip, hostname, cfg);
+  cp->msg = &msg->header;
+  cp->shandle =
+      GNUNET_HELPER_send (cp->helper, &msg->header, GNUNET_NO, &clear_msg, cp);
+  if (NULL == cp->shandle)
+  {
+    GNUNET_free (msg);
+    GNUNET_TESTBED_controller_stop (cp);
+    return NULL;
+  }
+  return cp;
 }
 
 
 /**
  * Stop the controller process (also will terminate all peers and controllers
  * dependent on this controller).  This function blocks until the testbed has
- * been fully terminated (!).
+ * been fully terminated (!). The controller status cb from
+ * GNUNET_TESTBED_controller_start() will not be called.
  *
  * @param cproc the controller process handle
  */
 void
 GNUNET_TESTBED_controller_stop (struct GNUNET_TESTBED_ControllerProc *cproc)
 {
-  GNUNET_TESTBED_host_stop_ (cproc->helper);
+  if (NULL != cproc->shandle)
+    GNUNET_HELPER_send_cancel (cproc->shandle);
+  if (NULL != cproc->helper)
+    GNUNET_HELPER_stop (cproc->helper);
+  if (NULL != cproc->cfg)
+    GNUNET_CONFIGURATION_destroy (cproc->cfg);
+  GNUNET_free_non_null (cproc->port);
+  GNUNET_free_non_null (cproc->dst);
   GNUNET_free (cproc);
 }
 
@@ -551,21 +1554,58 @@ GNUNET_TESTBED_controller_stop (struct GNUNET_TESTBED_ControllerProc *cproc)
  * @return handle to the controller
  */
 struct GNUNET_TESTBED_Controller *
-GNUNET_TESTBED_controller_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
-                                  struct GNUNET_TESTBED_Host *host,
-                                  uint64_t event_mask,
-                                  GNUNET_TESTBED_ControllerCallback cc,
-                                  void *cc_cls)
+GNUNET_TESTBED_controller_connect (const struct GNUNET_CONFIGURATION_Handle
+                                   *cfg, struct GNUNET_TESTBED_Host *host,
+                                   uint64_t event_mask,
+                                   GNUNET_TESTBED_ControllerCallback cc,
+                                   void *cc_cls)
 {
   struct GNUNET_TESTBED_Controller *controller;
   struct GNUNET_TESTBED_InitMessage *msg;
-
+  const char *controller_hostname;
+  unsigned long long max_parallel_operations;
+  unsigned long long max_parallel_service_connections;
+  unsigned long long max_parallel_topology_config_operations;
+  unsigned long long max_parallel_overlay_connect_operations;
+
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_number (cfg, "testbed",
+                                             "MAX_PARALLEL_OPERATIONS",
+                                             &max_parallel_operations))
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_number (cfg, "testbed",
+                                             "MAX_PARALLEL_SERVICE_CONNECTIONS",
+                                             &max_parallel_service_connections))
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_number (cfg, "testbed",
+                                             "MAX_PARALLEL_TOPOLOGY_CONFIG_OPERATIONS",
+                                             &max_parallel_topology_config_operations))
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_number (cfg, "testbed",
+                                             "MAX_PARALLEL_OVERLAY_CONNECT_OPERATIONS",
+                                             &max_parallel_overlay_connect_operations))
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
   controller = GNUNET_malloc (sizeof (struct GNUNET_TESTBED_Controller));
   controller->cc = cc;
   controller->cc_cls = cc_cls;
   controller->event_mask = event_mask;
   controller->cfg = GNUNET_CONFIGURATION_dup (cfg);
-  controller->client = GNUNET_CLIENT_connect ("testbed", controller->cfg);  
+  controller->client = GNUNET_CLIENT_connect ("testbed", controller->cfg);
   if (NULL == controller->client)
   {
     GNUNET_TESTBED_controller_disconnect (controller);
@@ -574,11 +1614,11 @@ GNUNET_TESTBED_controller_connect (const struct GNUNET_CONFIGURATION_Handle *cfg
   if (NULL == host)
   {
     host = GNUNET_TESTBED_host_create_by_id_ (0);
-    if (NULL == host)
+    if (NULL == host)           /* If the above host create fails */
     {
       LOG (GNUNET_ERROR_TYPE_WARNING,
-          "Treating NULL host as localhost. Multiple references to localhost. "
-          " May break when localhost freed before calling disconnect \n");
+           "Treating NULL host as localhost. Multiple references to localhost "
+           "may break when localhost freed before calling disconnect \n");
       host = GNUNET_TESTBED_host_lookup_by_id_ (0);
     }
     else
@@ -587,12 +1627,35 @@ GNUNET_TESTBED_controller_connect (const struct GNUNET_CONFIGURATION_Handle *cfg
     }
   }
   GNUNET_assert (NULL != host);
-  msg = GNUNET_malloc (sizeof (struct GNUNET_TESTBED_InitMessage));
+  GNUNET_TESTBED_mark_host_registered_at_ (host, controller);
+  controller->host = host;
+  controller->opq_parallel_operations =
+      GNUNET_TESTBED_operation_queue_create_ ((unsigned int)
+                                              max_parallel_operations);
+  controller->opq_parallel_service_connections =
+      GNUNET_TESTBED_operation_queue_create_ ((unsigned int)
+                                              max_parallel_service_connections);
+  controller->opq_parallel_topology_config_operations=
+      GNUNET_TESTBED_operation_queue_create_ ((unsigned int)
+                                              max_parallel_topology_config_operations);
+  controller->opq_parallel_overlay_connect_operations=
+      GNUNET_TESTBED_operation_queue_create_ ((unsigned int)
+                                              max_parallel_overlay_connect_operations);
+  controller_hostname = GNUNET_TESTBED_host_get_hostname_ (host);
+  if (NULL == controller_hostname)
+    controller_hostname = "127.0.0.1";
+  msg =
+      GNUNET_malloc (sizeof (struct GNUNET_TESTBED_InitMessage) +
+                     strlen (controller_hostname) + 1);
   msg->header.type = htons (GNUNET_MESSAGE_TYPE_TESTBED_INIT);
-  msg->header.size = htons (sizeof (struct GNUNET_TESTBED_InitMessage));
+  msg->header.size =
+      htons (sizeof (struct GNUNET_TESTBED_InitMessage) +
+             strlen (controller_hostname) + 1);
   msg->host_id = htonl (GNUNET_TESTBED_host_get_id_ (host));
   msg->event_mask = GNUNET_htonll (controller->event_mask);
-  GNUNET_TESTBED_queue_message (controller, (struct GNUNET_MessageHeader *) msg);
+  strcpy ((char *) &msg[1], controller_hostname);
+  GNUNET_TESTBED_queue_message_ (controller,
+                                 (struct GNUNET_MessageHeader *) msg);
   return controller;
 }
 
@@ -603,7 +1666,7 @@ GNUNET_TESTBED_controller_connect (const struct GNUNET_CONFIGURATION_Handle *cfg
  * should not be run for each peer but instead be shared
  * across N peers on the specified host.  This function
  * must be called before any peers are created at the host.
- * 
+ *
  * @param controller controller to configure
  * @param service_name name of the service to share
  * @param num_peers number of peers that should share one instance
@@ -611,24 +1674,29 @@ GNUNET_TESTBED_controller_connect (const struct GNUNET_CONFIGURATION_Handle *cfg
  *        use 0 to disable the service
  */
 void
-GNUNET_TESTBED_controller_configure_sharing (struct GNUNET_TESTBED_Controller *controller,
-                                            const char *service_name,
-                                            uint32_t num_peers)
+GNUNET_TESTBED_controller_configure_sharing (struct GNUNET_TESTBED_Controller
+                                             *controller,
+                                             const char *service_name,
+                                             uint32_t num_peers)
 {
   struct GNUNET_TESTBED_ConfigureSharedServiceMessage *msg;
   uint16_t service_name_size;
   uint16_t msg_size;
-  
+
   service_name_size = strlen (service_name) + 1;
-  msg_size = sizeof (struct GNUNET_TESTBED_ConfigureSharedServiceMessage)
-    + service_name_size;
+  msg_size =
+      sizeof (struct GNUNET_TESTBED_ConfigureSharedServiceMessage) +
+      service_name_size;
   msg = GNUNET_malloc (msg_size);
   msg->header.size = htons (msg_size);
   msg->header.type = htons (GNUNET_MESSAGE_TYPE_TESTBED_SERVICESHARE);
   msg->host_id = htonl (GNUNET_TESTBED_host_get_id_ (controller->host));
   msg->num_peers = htonl (num_peers);
   memcpy (&msg[1], service_name, service_name_size);
-  GNUNET_TESTBED_queue_message (controller, (struct GNUNET_MessageHeader *) msg);
+  GNUNET_TESTBED_queue_message_ (controller,
+                                 (struct GNUNET_MessageHeader *) msg);
+  GNUNET_break (0);             /* This function is not yet implemented on the
+                                   testbed service */
 }
 
 
@@ -638,18 +1706,18 @@ GNUNET_TESTBED_controller_configure_sharing (struct GNUNET_TESTBED_Controller *c
  * @param controller handle to controller to stop
  */
 void
-GNUNET_TESTBED_controller_disconnect (struct GNUNET_TESTBED_Controller *controller)
+GNUNET_TESTBED_controller_disconnect (struct GNUNET_TESTBED_Controller
+                                      *controller)
 {
   struct MessageQueue *mq_entry;
 
   if (NULL != controller->th)
     GNUNET_CLIENT_notify_transmit_ready_cancel (controller->th);
- /* Clear the message queue */
 /* Clear the message queue */
   while (NULL != (mq_entry = controller->mq_head))
   {
-    GNUNET_CONTAINER_DLL_remove (controller->mq_head,
-                                controller->mq_tail,
-                                mq_entry);
+    GNUNET_CONTAINER_DLL_remove (controller->mq_head, controller->mq_tail,
+                                 mq_entry);
     GNUNET_free (mq_entry->msg);
     GNUNET_free (mq_entry);
   }
@@ -658,6 +1726,13 @@ GNUNET_TESTBED_controller_disconnect (struct GNUNET_TESTBED_Controller *controll
   GNUNET_CONFIGURATION_destroy (controller->cfg);
   if (GNUNET_YES == controller->aux_host)
     GNUNET_TESTBED_host_destroy (controller->host);
+  GNUNET_TESTBED_operation_queue_destroy_ (controller->opq_parallel_operations);
+  GNUNET_TESTBED_operation_queue_destroy_
+      (controller->opq_parallel_service_connections);
+  GNUNET_TESTBED_operation_queue_destroy_
+      (controller->opq_parallel_topology_config_operations);
+  GNUNET_TESTBED_operation_queue_destroy_
+      (controller->opq_parallel_overlay_connect_operations);
   GNUNET_free (controller);
 }
 
@@ -672,7 +1747,7 @@ GNUNET_TESTBED_controller_disconnect (struct GNUNET_TESTBED_Controller *controll
  *          will be invalid. Cannot be NULL.
  * @param cc_cls the closure for the cc
  * @return handle to the host registration which can be used to cancel the
- *           registration 
+ *           registration
  */
 struct GNUNET_TESTBED_HostRegistrationHandle *
 GNUNET_TESTBED_register_host (struct GNUNET_TESTBED_Controller *controller,
@@ -692,11 +1767,10 @@ GNUNET_TESTBED_register_host (struct GNUNET_TESTBED_Controller *controller,
   hostname = GNUNET_TESTBED_host_get_hostname_ (host);
   if (GNUNET_YES == GNUNET_TESTBED_is_host_registered_ (host, controller))
   {
-    LOG (GNUNET_ERROR_TYPE_WARNING,
-         "Host hostname: %s already registered\n",
+    LOG (GNUNET_ERROR_TYPE_WARNING, "Host hostname: %s already registered\n",
          (NULL == hostname) ? "localhost" : hostname);
     return NULL;
-  }  
+  }
   rh = GNUNET_malloc (sizeof (struct GNUNET_TESTBED_HostRegistrationHandle));
   rh->host = host;
   rh->c = controller;
@@ -720,11 +1794,16 @@ GNUNET_TESTBED_register_host (struct GNUNET_TESTBED_Controller *controller,
   msg->header.type = htons (GNUNET_MESSAGE_TYPE_TESTBED_ADDHOST);
   msg->host_id = htonl (GNUNET_TESTBED_host_get_id_ (host));
   msg->ssh_port = htons (GNUNET_TESTBED_host_get_ssh_port_ (host));
-  msg->user_name_length = htons (user_name_length);
   if (NULL != username)
+  {
+    msg->user_name_length = htons (user_name_length - 1);
     memcpy (&msg[1], username, user_name_length);
+  }
+  else
+    msg->user_name_length = htons (user_name_length);
   strcpy (((void *) &msg[1]) + user_name_length, hostname);
-  GNUNET_TESTBED_queue_message (controller, (struct GNUNET_MessageHeader *) msg);
+  GNUNET_TESTBED_queue_message_ (controller,
+                                 (struct GNUNET_MessageHeader *) msg);
   return rh;
 }
 
@@ -746,53 +1825,116 @@ GNUNET_TESTBED_cancel_registration (struct GNUNET_TESTBED_HostRegistrationHandle
     return;
   }
   handle->c->rh = NULL;
-  GNUNET_free (handle);  
+  GNUNET_free (handle);
 }
 
 
 /**
- * Same as the GNUNET_TESTBED_controller_link, however expects configuration in
- * serialized and compressed
+ * Same as the GNUNET_TESTBED_controller_link_2, but with ids for delegated host
+ * and slave host
  *
+ * @param op_cls the operation closure for the event which is generated to
+ *          signal success or failure of this operation
  * @param master handle to the master controller who creates the association
- * @param delegated_host requests to which host should be delegated; cannot be NULL
- * @param slave_host which host is used to run the slave controller; use NULL to
- *          make the master controller connect to the delegated host
+ * @param delegated_host_id id of the host to which requests should be delegated
+ * @param slave_host_id id of the host which is used to run the slave controller
  * @param sxcfg serialized and compressed configuration
- * @param sxcfg_size the size scfg
+ * @param sxcfg_size the size sxcfg
  * @param scfg_size the size of uncompressed serialized configuration
  * @param is_subordinate GNUNET_YES if the controller at delegated_host should
- *          be started by the master controller; GNUNET_NO if we are just
- *          allowed to use the slave via TCP/IP
+ *          be started by the slave controller; GNUNET_NO if the slave
+ *          controller has to connect to the already started delegated
+ *          controller via TCP/IP
+ * @return the operation handle
  */
-void
-GNUNET_TESTBED_controller_link_2 (struct GNUNET_TESTBED_Controller *master,
-                                 struct GNUNET_TESTBED_Host *delegated_host,
-                                 struct GNUNET_TESTBED_Host *slave_host,
-                                 const char *sxcfg,
-                                 size_t sxcfg_size,
-                                 size_t scfg_size,
-                                 int is_subordinate)
+struct GNUNET_TESTBED_Operation *
+GNUNET_TESTBED_controller_link_2_ (void *op_cls,
+                                   struct GNUNET_TESTBED_Controller *master,
+                                   uint32_t delegated_host_id,
+                                   uint32_t slave_host_id,
+                                   const char *sxcfg, size_t sxcfg_size,
+                                   size_t scfg_size, int is_subordinate)
 {
+  struct OperationContext *opc;
   struct GNUNET_TESTBED_ControllerLinkMessage *msg;
+  struct ControllerLinkData *data;
   uint16_t msg_size;
 
-  GNUNET_assert (GNUNET_YES == 
-                GNUNET_TESTBED_is_host_registered_ (delegated_host, master));
-  if ((NULL != slave_host) && (0 != GNUNET_TESTBED_host_get_id_ (slave_host)))
-    GNUNET_assert (GNUNET_YES == 
-                  GNUNET_TESTBED_is_host_registered_ (slave_host, master));
   msg_size = sxcfg_size + sizeof (struct GNUNET_TESTBED_ControllerLinkMessage);
   msg = GNUNET_malloc (msg_size);
-  msg->header.type = htons (GNUNET_MESSAGE_TYPE_TESTBED_LCONTROLLERS);  
+  msg->header.type = htons (GNUNET_MESSAGE_TYPE_TESTBED_LCONTROLLERS);
   msg->header.size = htons (msg_size);
-  msg->delegated_host_id = htonl (GNUNET_TESTBED_host_get_id_ (delegated_host));
-  msg->slave_host_id = htonl (GNUNET_TESTBED_host_get_id_ 
-                             ((NULL != slave_host) ? slave_host : master->host));
+  msg->delegated_host_id = htonl (delegated_host_id);
+  msg->slave_host_id = htonl (slave_host_id);
   msg->config_size = htons ((uint16_t) scfg_size);
   msg->is_subordinate = (GNUNET_YES == is_subordinate) ? 1 : 0;
   memcpy (&msg[1], sxcfg, sxcfg_size);
-  GNUNET_TESTBED_queue_message (master, (struct GNUNET_MessageHeader *) msg);
+  data = GNUNET_malloc (sizeof (struct ControllerLinkData));
+  data->msg = msg;
+  opc = GNUNET_malloc (sizeof (struct OperationContext));
+  opc->c = master;
+  opc->data = data;
+  opc->type = OP_LINK_CONTROLLERS;
+  opc->id = GNUNET_TESTBED_get_next_op_id (opc->c);
+  opc->state = OPC_STATE_INIT;
+  opc->op_cls = op_cls;
+  msg->operation_id = GNUNET_htonll (opc->id);
+  opc->op =
+      GNUNET_TESTBED_operation_create_ (opc, &opstart_link_controllers,
+                                        &oprelease_link_controllers);
+  GNUNET_TESTBED_operation_queue_insert_ (master->opq_parallel_operations,
+                                          opc->op);
+  return opc->op;
+}
+
+
+/**
+ * Same as the GNUNET_TESTBED_controller_link, however expects configuration in
+ * serialized and compressed
+ *
+ * @param op_cls the operation closure for the event which is generated to
+ *          signal success or failure of this operation
+ * @param master handle to the master controller who creates the association
+ * @param delegated_host requests to which host should be delegated; cannot be NULL
+ * @param slave_host which host is used to run the slave controller; use NULL to
+ *          make the master controller connect to the delegated host
+ * @param sxcfg serialized and compressed configuration
+ * @param sxcfg_size the size sxcfg
+ * @param scfg_size the size of uncompressed serialized configuration
+ * @param is_subordinate GNUNET_YES if the controller at delegated_host should
+ *          be started by the slave controller; GNUNET_NO if the slave
+ *          controller has to connect to the already started delegated
+ *          controller via TCP/IP
+ * @return the operation handle
+ */
+struct GNUNET_TESTBED_Operation *
+GNUNET_TESTBED_controller_link_2 (void *op_cls,
+                                 struct GNUNET_TESTBED_Controller *master,
+                                  struct GNUNET_TESTBED_Host *delegated_host,
+                                  struct GNUNET_TESTBED_Host *slave_host,
+                                  const char *sxcfg, size_t sxcfg_size,
+                                  size_t scfg_size, int is_subordinate)
+{ 
+  uint32_t delegated_host_id;
+  uint32_t slave_host_id;
+
+  GNUNET_assert (GNUNET_YES ==
+                 GNUNET_TESTBED_is_host_registered_ (delegated_host, master));
+  delegated_host_id = GNUNET_TESTBED_host_get_id_ (delegated_host);
+  slave_host_id = 
+      GNUNET_TESTBED_host_get_id_ ((NULL != slave_host)
+                                   ? slave_host : master->host);
+  if ((NULL != slave_host) && (0 != GNUNET_TESTBED_host_get_id_ (slave_host)))
+    GNUNET_assert (GNUNET_YES ==
+                   GNUNET_TESTBED_is_host_registered_ (slave_host, master));
+  
+  return GNUNET_TESTBED_controller_link_2_ (op_cls,
+                                            master,
+                                            delegated_host_id,
+                                            slave_host_id,
+                                            sxcfg, sxcfg_size,
+                                            scfg_size, is_subordinate);
+  GNUNET_break (0);
 }
 
 
@@ -802,72 +1944,194 @@ GNUNET_TESTBED_controller_link_2 (struct GNUNET_TESTBED_Controller *master,
  * @param config the serialized configuration
  * @param size the size of config
  * @param xconfig will be set to the compressed configuration (memory is fresly
- *          allocated) 
+ *          allocated)
  * @return the size of the xconfig
  */
 size_t
-GNUNET_TESTBED_compress_config (const char *config, size_t size,
-                                char **xconfig)
+GNUNET_TESTBED_compress_config_ (const char *config, size_t size,
+                                 char **xconfig)
 {
   size_t xsize;
-  
+
   xsize = compressBound ((uLong) size);
   *xconfig = GNUNET_malloc (xsize);
   GNUNET_assert (Z_OK ==
-                compress2 ((Bytef *)* xconfig, (uLongf *) &xsize,
-                            (const Bytef *) config, (uLongf) size, 
+                 compress2 ((Bytef *) * xconfig, (uLongf *) & xsize,
+                            (const Bytef *) config, (uLongf) size,
                             Z_BEST_SPEED));
   return xsize;
 }
-                                
+
 
 /**
- * Create a link from slave controller to delegated controller. Whenever the
- * master controller is asked to start a peer at the delegated controller the
- * request will be routed towards slave controller (if a route exists). The
- * slave controller will then route it to the delegated controller. The
- * configuration of the slave controller is given and to be used to either
- * create the slave controller or to connect to an existing slave controller
- * process.  'is_subordinate' specifies if the given slave controller should be
- * started and managed by the master controller, or if the slave already has a
- * master and this is just a secondary master that is also allowed to use the
- * existing slave.
+ * Same as the GNUNET_TESTBED_controller_link, but with ids for delegated host
+ * and slave host
  *
+ * @param op_cls the operation closure for the event which is generated to
+ *          signal success or failure of this operation
  * @param master handle to the master controller who creates the association
- * @param delegated_host requests to which host should be delegated
- * @param slave_host which host is used to run the slave controller 
+ * @param delegated_host_id id of the host to which requests should be
+ *          delegated; cannot be NULL
+ * @param slave_host_id id of the host which should connect to controller
+ *          running on delegated host ; use NULL to make the master controller
+ *          connect to the delegated host
  * @param slave_cfg configuration to use for the slave controller
- * @param is_subordinate GNUNET_YES if the slave should be started (and stopped)
- *                       by the master controller; GNUNET_NO if we are just
- *                       allowed to use the slave via TCP/IP
+ * @param is_subordinate GNUNET_YES if the controller at delegated_host should
+ *          be started by the slave controller; GNUNET_NO if the slave
+ *          controller has to connect to the already started delegated
+ *          controller via TCP/IP
+ * @return the operation handle
  */
-void
-GNUNET_TESTBED_controller_link (struct GNUNET_TESTBED_Controller *master,
-                               struct GNUNET_TESTBED_Host *delegated_host,
-                               struct GNUNET_TESTBED_Host *slave_host,
-                               const struct GNUNET_CONFIGURATION_Handle *slave_cfg,
-                               int is_subordinate)
+struct GNUNET_TESTBED_Operation *
+GNUNET_TESTBED_controller_link_ (void *op_cls,
+                               struct GNUNET_TESTBED_Controller *master,
+                                uint32_t delegated_host_id,
+                                uint32_t slave_host_id,
+                                const struct GNUNET_CONFIGURATION_Handle
+                                *slave_cfg,
+                                int is_subordinate)
 {
+  struct GNUNET_TESTBED_Operation *op;
   char *config;
   char *cconfig;
   size_t cc_size;
-  size_t config_size;  
-  
-  GNUNET_assert (GNUNET_YES == 
-                GNUNET_TESTBED_is_host_registered_ (delegated_host, master));
-  if ((NULL != slave_host) && (0 != GNUNET_TESTBED_host_get_id_ (slave_host)))
-    GNUNET_assert (GNUNET_YES == 
-                  GNUNET_TESTBED_is_host_registered_ (slave_host, master));
+  size_t config_size;
+
   config = GNUNET_CONFIGURATION_serialize (slave_cfg, &config_size);
-  cc_size = GNUNET_TESTBED_compress_config (config, config_size, &cconfig);
+  cc_size = GNUNET_TESTBED_compress_config_ (config, config_size, &cconfig);
   GNUNET_free (config);
-  GNUNET_assert ((UINT16_MAX -
-                 sizeof (struct GNUNET_TESTBED_ControllerLinkMessage))
-                 >= cc_size); /* Configuration doesn't fit in 1 message */
-  GNUNET_TESTBED_controller_link_2 (master, delegated_host, slave_host,
-                                   (const char *) cconfig,
-                                   cc_size, config_size, is_subordinate);
+  /* Configuration doesn't fit in 1 message */
+  GNUNET_assert ((UINT16_MAX - 
+                 sizeof (struct GNUNET_TESTBED_ControllerLinkMessage)) >=
+                 cc_size);
+  op = GNUNET_TESTBED_controller_link_2_ (op_cls, master, delegated_host_id,
+                                          slave_host_id, (const char *) cconfig,
+                                          cc_size, config_size, is_subordinate);
   GNUNET_free (cconfig);
+  return op;
+}
+
+
+/**
+ * Create a link from slave controller to delegated controller. Whenever the
+ * master controller is asked to start a peer at the delegated controller the
+ * request will be routed towards slave controller (if a route exists). The
+ * slave controller will then route it to the delegated controller. The
+ * configuration of the delegated controller is given and is used to either
+ * create the delegated controller or to connect to an existing controller. Note
+ * that while starting the delegated controller the configuration will be
+ * modified to accommodate available free ports.  the 'is_subordinate' specifies
+ * if the given delegated controller should be started and managed by the slave
+ * controller, or if the delegated controller already has a master and the slave
+ * controller connects to it as a non master controller. The success or failure
+ * of this operation will be signalled through the
+ * GNUNET_TESTBED_ControllerCallback() with an event of type
+ * GNUNET_TESTBED_ET_OPERATION_FINISHED
+ *
+ * @param op_cls the operation closure for the event which is generated to
+ *          signal success or failure of this operation
+ * @param master handle to the master controller who creates the association
+ * @param delegated_host requests to which host should be delegated; cannot be NULL
+ * @param slave_host which host is used to run the slave controller; use NULL to
+ *          make the master controller connect to the delegated host
+ * @param slave_cfg configuration to use for the slave controller
+ * @param is_subordinate GNUNET_YES if the controller at delegated_host should
+ *          be started by the slave controller; GNUNET_NO if the slave
+ *          controller has to connect to the already started delegated
+ *          controller via TCP/IP
+ * @return the operation handle
+ */
+struct GNUNET_TESTBED_Operation *
+GNUNET_TESTBED_controller_link (void *op_cls,
+                               struct GNUNET_TESTBED_Controller *master,
+                                struct GNUNET_TESTBED_Host *delegated_host,
+                                struct GNUNET_TESTBED_Host *slave_host,
+                                const struct GNUNET_CONFIGURATION_Handle
+                                *slave_cfg, int is_subordinate)
+{
+  uint32_t slave_host_id;
+  uint32_t delegated_host_id;
+
+  GNUNET_assert (GNUNET_YES ==
+                 GNUNET_TESTBED_is_host_registered_ (delegated_host, master));
+  slave_host_id = 
+      GNUNET_TESTBED_host_get_id_ ((NULL != slave_host)
+                                   ? slave_host : master->host);
+  delegated_host_id = GNUNET_TESTBED_host_get_id_ (delegated_host);
+  if ((NULL != slave_host) && (0 != slave_host_id))
+    GNUNET_assert (GNUNET_YES ==
+                   GNUNET_TESTBED_is_host_registered_ (slave_host, master));
+  return GNUNET_TESTBED_controller_link_ (op_cls, master,
+                                          delegated_host_id,
+                                          slave_host_id,
+                                          slave_cfg,
+                                          is_subordinate);
+                                          
+}
+
+
+/**
+ * Like GNUNET_TESTBED_get_slave_config(), however without the host registration
+ * check. Another difference is that this function takes the id of the slave
+ * host.
+ *
+ * @param op_cls the closure for the operation
+ * @param master the handle to master controller
+ * @param slave_host_id id of the host where the slave controller is running to
+ *          the slave_host should remain valid until this operation is cancelled
+ *          or marked as finished
+ * @return the operation handle;
+ */
+struct GNUNET_TESTBED_Operation *
+GNUNET_TESTBED_get_slave_config_ (void *op_cls,
+                                  struct GNUNET_TESTBED_Controller *master,
+                                  uint32_t slave_host_id)
+{  
+  struct OperationContext *opc;
+  struct GetSlaveConfigData *data;
+
+  data = GNUNET_malloc (sizeof (struct GetSlaveConfigData));
+  data->slave_id = slave_host_id;
+  opc = GNUNET_malloc (sizeof (struct OperationContext));
+  opc->state = OPC_STATE_INIT;
+  opc->c = master;
+  opc->id = GNUNET_TESTBED_get_next_op_id (master);
+  opc->type = OP_GET_SLAVE_CONFIG;
+  opc->data = data;
+  opc->op_cls = op_cls;
+  opc->op =
+      GNUNET_TESTBED_operation_create_ (opc, &opstart_get_slave_config,
+                                        &oprelease_get_slave_config);
+  GNUNET_TESTBED_operation_queue_insert_ (master->opq_parallel_operations,
+                                         opc->op); 
+  return opc->op;
+}
+
+
+/**
+ * Function to acquire the configuration of a running slave controller. The
+ * completion of the operation is signalled through the controller_cb from
+ * GNUNET_TESTBED_controller_connect(). If the operation is successful the
+ * handle to the configuration is available in the generic pointer of
+ * operation_finished field of struct GNUNET_TESTBED_EventInformation.
+ *
+ * @param op_cls the closure for the operation
+ * @param master the handle to master controller
+ * @param slave_host the host where the slave controller is running; the handle
+ *          to the slave_host should remain valid until this operation is
+ *          cancelled or marked as finished
+ * @return the operation handle; NULL if the slave_host is not registered at
+ *           master
+ */
+struct GNUNET_TESTBED_Operation *
+GNUNET_TESTBED_get_slave_config (void *op_cls,
+                                 struct GNUNET_TESTBED_Controller *master,
+                                 struct GNUNET_TESTBED_Host *slave_host)
+{
+  if (GNUNET_NO == GNUNET_TESTBED_is_host_registered_ (slave_host, master))
+    return NULL;
+  return GNUNET_TESTBED_get_slave_config_ (op_cls, master,
+                                           GNUNET_TESTBED_host_get_id_ (slave_host));
 }
 
 
@@ -881,12 +2145,218 @@ GNUNET_TESTBED_controller_link (struct GNUNET_TESTBED_Controller *master,
  *        be written to.
  */
 void
-GNUNET_TESTBED_overlay_write_topology_to_file (struct GNUNET_TESTBED_Controller *controller,
-                                              const char *filename)
+GNUNET_TESTBED_overlay_write_topology_to_file (struct GNUNET_TESTBED_Controller
+                                               *controller,
+                                               const char *filename)
 {
   GNUNET_break (0);
 }
 
 
+/**
+ * Creates a helper initialization message. This function is here because we
+ * want to use this in testing
+ *
+ * @param cname the ip address of the controlling host
+ * @param hostname the hostname of the destination this message is intended for
+ * @param cfg the configuration that has to used to start the testbed service
+ *          thru helper
+ * @return the initialization message
+ */
+struct GNUNET_TESTBED_HelperInit *
+GNUNET_TESTBED_create_helper_init_msg_ (const char *cname,
+                                       const char *hostname,
+                                        const struct GNUNET_CONFIGURATION_Handle
+                                        *cfg)
+{
+  struct GNUNET_TESTBED_HelperInit *msg;
+  char *config;
+  char *xconfig;
+  size_t config_size;
+  size_t xconfig_size;
+  uint16_t cname_len;
+  uint16_t hostname_len;
+  uint16_t msg_size;
+
+  config = GNUNET_CONFIGURATION_serialize (cfg, &config_size);
+  GNUNET_assert (NULL != config);
+  xconfig_size =
+      GNUNET_TESTBED_compress_config_ (config, config_size, &xconfig);
+  GNUNET_free (config);
+  cname_len = strlen (cname);
+  hostname_len = (NULL == hostname) ? 0 : strlen (hostname);
+  msg_size =
+      xconfig_size + cname_len + 1 + sizeof (struct GNUNET_TESTBED_HelperInit);
+  msg_size += hostname_len;
+  msg = GNUNET_realloc (xconfig, msg_size);
+  (void) memmove (((void *) &msg[1]) + cname_len + 1 + hostname_len,
+                 msg,
+                 xconfig_size);
+  msg->header.size = htons (msg_size);
+  msg->header.type = htons (GNUNET_MESSAGE_TYPE_TESTBED_HELPER_INIT);
+  msg->cname_size = htons (cname_len);
+  msg->hostname_size = htons (hostname_len);
+  msg->config_size = htons (config_size);
+  (void) strcpy ((char *) &msg[1], cname);
+  if (0 != hostname_len)
+    (void) strncpy (((char *) &msg[1]) + cname_len + 1, hostname, hostname_len);
+  return msg;
+}
+
+
+/**
+ * Cancel a pending operation.  Releases all resources
+ * of the operation and will ensure that no event
+ * is generated for the operation.  Does NOT guarantee
+ * that the operation will be fully undone (or that
+ * nothing ever happened).
+ *
+ * @param operation operation to cancel
+ */
+void
+GNUNET_TESTBED_operation_cancel (struct GNUNET_TESTBED_Operation *operation)
+{
+  GNUNET_TESTBED_operation_done (operation);
+}
+
+
+/**
+ * Signal that the information from an operation has been fully
+ * processed.  This function MUST be called for each event
+ * of type 'operation_finished' to fully remove the operation
+ * from the operation queue.  After calling this function, the
+ * 'op_result' becomes invalid (!).
+ *
+ * @param operation operation to signal completion for
+ */
+void
+GNUNET_TESTBED_operation_done (struct GNUNET_TESTBED_Operation *operation)
+{
+  switch (operation->type)
+  {
+  case OP_PEER_CREATE:
+  case OP_PEER_DESTROY:
+  case OP_PEER_START:
+  case OP_PEER_STOP:
+  case OP_PEER_INFO:
+  case OP_OVERLAY_CONNECT:
+  case OP_LINK_CONTROLLERS:
+    GNUNET_TESTBED_operation_release_ (operation);
+    return;
+  default:
+    GNUNET_assert (0);
+    break;
+  }
+}
+
+
+/**
+ * Generates configuration by uncompressing configuration in given message. The
+ * given message should be of the following types:
+ * GNUNET_MESSAGE_TYPE_TESTBED_PEERCONFIG,
+ * GNUNET_MESSAGE_TYPE_TESTBED_SLAVECONFIG
+ *
+ * @param msg the message containing compressed configuration
+ * @return handle to the parsed configuration
+ */
+struct GNUNET_CONFIGURATION_Handle *
+GNUNET_TESTBED_extract_config_ (const struct GNUNET_MessageHeader *msg)
+{  
+  struct GNUNET_CONFIGURATION_Handle *cfg;
+  Bytef *data;
+  const Bytef *xdata;
+  uLong data_len;
+  uLong xdata_len;
+  int ret;
+
+  switch (ntohs (msg->type))
+  {
+  case GNUNET_MESSAGE_TYPE_TESTBED_PEERCONFIG:
+    {
+      const struct GNUNET_TESTBED_PeerConfigurationInformationMessage *imsg;
+
+      imsg = (const struct GNUNET_TESTBED_PeerConfigurationInformationMessage *)
+         msg;
+      data_len = (uLong) ntohs (imsg->config_size);
+      xdata_len = ntohs (imsg->header.size)
+         - sizeof (struct GNUNET_TESTBED_PeerConfigurationInformationMessage);
+      xdata = (const Bytef *) &imsg[1];
+    }
+    break;
+  case GNUNET_MESSAGE_TYPE_TESTBED_SLAVECONFIG:
+    {
+      const struct GNUNET_TESTBED_SlaveConfiguration *imsg;
+
+      imsg = (const struct GNUNET_TESTBED_SlaveConfiguration *) msg;
+      data_len = (uLong) ntohs (imsg->config_size);
+      xdata_len =  ntohs (imsg->header.size) 
+         - sizeof (struct GNUNET_TESTBED_SlaveConfiguration);
+      xdata = (const Bytef *) &imsg[1];
+    }
+    break;
+  default:
+    GNUNET_assert (0);
+  }  
+  data = GNUNET_malloc (data_len);
+  if (Z_OK !=
+      (ret =
+       uncompress (data, &data_len, xdata, xdata_len)))
+    GNUNET_assert (0);
+  cfg = GNUNET_CONFIGURATION_create ();
+  GNUNET_assert (GNUNET_OK ==
+                 GNUNET_CONFIGURATION_deserialize (cfg, (const char *) data,
+                                                   (size_t) data_len,
+                                                   GNUNET_NO));
+  GNUNET_free (data);
+  return cfg;
+}
+
+
+/**
+ * Checks the integrity of the OperationFailureEventMessage and if good returns
+ * the error message it contains.
+ *
+ * @param msg the OperationFailureEventMessage
+ * @return the error message
+ */
+const char *
+GNUNET_TESTBED_parse_error_string_ (const struct
+                                    GNUNET_TESTBED_OperationFailureEventMessage
+                                    *msg)
+{
+  uint16_t msize;
+  const char *emsg;
+  
+  msize = ntohs (msg->header.size);
+  if (sizeof (struct GNUNET_TESTBED_OperationFailureEventMessage) >= msize)
+    return NULL;
+  msize -= sizeof (struct GNUNET_TESTBED_OperationFailureEventMessage);
+  emsg = (const char *) &msg[1];
+  if ('\0' != emsg[msize - 1])
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  return emsg;
+}
+
+
+/**
+ * Function to return the operation id for a controller. The operation id is
+ * created from the controllers host id and its internal operation counter.
+ *
+ * @param controller the handle to the controller whose operation id has to be incremented
+ * @return the incremented operation id.
+ */
+uint64_t
+GNUNET_TESTBED_get_next_op_id (struct GNUNET_TESTBED_Controller *controller)
+{
+  uint64_t op_id;  
+
+  op_id = (uint64_t) GNUNET_TESTBED_host_get_id_ (controller->host);
+  op_id = op_id <<  32;
+  op_id |= (uint64_t) controller->operation_counter++;
+  return op_id;
+}
 
 /* end of testbed_api.c */